Narrow bandpass optical filter design with defected ternary photonic crystal under p-Polarized incidence

Optical bandwidth of defected ternary photonic crystal is analytically computed under oblique incidence. P-polarized is considered for incidence on the structure, and result is compared with that obtained under normal incidence. Intentionally defect is incorporated within feasible limit for narrow bandpass filter design; and layer dimension is tuned to observe the variation around 1550 nm. It is observed that passband with ripple can suitably be tailored by varying the defect density. Critical dimension is predicted for different layers over which the effect of sandwiched layer becomes insignificant, i.e., the structure will behave as binary one. Result is important for design of filter when noise spectrum is closely spaced with desired signal for optical communication.